(1R-trans)-N-[[2-(2,3-dihydro-4-benzofuranyl)cyclopropyl]methyl]propanamide, a specific and potent agonist of the MT1R and MT2R melatonin receptors in the suprachiasmatic nucleus (SCN), is described in U.S. Pat. No. 5,856,529, which is incorporated herein by reference as though fully set forth. Engagement of the MT1R and MT2R receptors by melatonin is believed to regulate circadian rhythms, including the sleep/wake cycle. (1R-trans)-N-[[2-(2,3-dihydro-4-benzofuranyl)cyclopropyl]methyl]-propanamide is well-tolerated and demonstrates potent chronobiotic activity in preclinical models of acute phase-shifting and chronic re-entrainment.